benchmark.rb

require 'benchmark'

namespace :benchmark do
  
  task :test => :environment do
    # Repeat these values 100 times
    values = [[
      {:timestamp => "2011-01-01 00:00", :value => 1},
      {:timestamp => "2011-01-01 00:15", :value => 2},
      {:timestamp => "2011-01-01 00:30", :value => 3}
    ],[
      {:timestamp => "2011-01-01 00:00", :value => 1},
      {:timestamp => "2011-01-01 00:30", :value => 3}
    ],[
      {:timestamp => "2011-01-01 00:00", :value => 1},
      {:timestamp => "2011-01-01 00:15", :value => 2},
      {:timestamp => "2011-01-01 00:30", :value => 3}
    ]].map{|x|[x]*100}.flatten(1)

    Benchmark.bmbm do |x|
      x.report("test 1") do 
        10_000.times do
          all_stamps = values.flatten.map{|x| x[:timestamp]}.uniq.sort
          values.each do |set|
            my_stamps=set.map{|x|x[:timestamp]}.uniq
            missing = all_stamps - my_stamps
            set.concat( missing.map{ |stamp| {:timestamp => stamp, :value => nil} } )
            set.replace( set.sort_by{ |x| x[:timestamp] } )
          end
        end
      end

      x.report("test2") do
        10_000.times do
          stamps = values.map{ |logs| logs.map{ |row| row[:timestamp] } }.flatten.uniq.sort
          values.map!{ |logs| stamps.map { |ts| logs.select{ |row| row[:timestamp] == ts }.first || { :timestamp => ts, :value => nil } } }
        end
      end
    end
  end
  
end